VB.net 反序列化，JSON 从类型“Dictionary(Of String,Object)”到“String”类型的转换

VB.net deserialize, JSON Conversion from type 'Dictionary(Of String,Object)' to type 'String'

提问by Keith Beard

So I have looked at many posts, but I am still struggling with serializing this JSON object into classes. The JSON structure is this

所以我看了很多帖子，但我仍然在努力将这个 JSON 对象序列化为类。JSON 结构是这样的

{"value":{"HashTag":"12342345636","companyname":"my test company","LeadDetail":{"id":"1","firstname":"john","lastname":"clark","email":"[email protected]","phone":"9874534444"}}}

{"value":{"HashTag":"12342345636","companyname":"my test company","LeadDetail":{"id":"1","firstname":"john","lastname":"clark","email":"[email protected]","phone":"9874534444"}}}

My class structure is as follows:

我的班级结构如下：

 <Serializable> _
Public Class LeadDetailCall
    Public Property Hash() As String
        Get
            Return m_Hash
        End Get
        Set(value As String)
            m_Hash = value
        End Set
    End Property

    Private m_Hash As String = ""
    Public Property CompanyName() As String
        Get
            Return _CompanyName
        End Get
        Set(value As String)
            _CompanyName = value
        End Set
    End Property
    Private _CompanyName As String = ""

    Public Property Details() As List(Of LeadDetail)
        Get
            Return _Details
        End Get
        Set(ByVal value As List(Of LeadDetail))
            _Details = value
        End Set
    End Property
    Private _Details As List(Of LeadDetail)
End Class
<Serializable> _
Public Class LeadDetail
    Private _id As String = ""
    Private _firstname As String = ""
    Private _lastname As String = ""
    Private _email As String = ""
    Private _phone As String = ""
    Public Property id() As String
        Get
            Return _id
        End Get
        Set(value As String)
            _id = value
        End Set
    End Property

    Public Property firstname() As String
        Get
            Return _firstname
        End Get
        Set(ByVal value As String)
            _firstname = value
        End Set
    End Property
    Public Property lastname() As String
        Get
            Return _lastname
        End Get
        Set(ByVal value As String)
            _lastname = value
        End Set
    End Property
    Public Property email() As String
        Get
            Return _email
        End Get
        Set(ByVal value As String)
            _email = value
        End Set
    End Property
    Public Property phone() As String
        Get
            Return _phone
        End Get
        Set(ByVal value As String)
            _phone = value
        End Set
    End Property
End Class

I call like so:

我这样称呼：

    <WebMethod()> _
Public Function SendLeadDetails(ByVal value As Object) As UpdateResponse
    Dim CurCall As LeadDetailCall = JsonConvert.DeserializeObject(Of LeadDetailCall)(value)
End Function

What have I tried? Using the JavaScriptSerializer, using http://jsontodatacontract.azurewebsites.net/crawling stackoverflow for examples. So many things that at this point I am flustered. So I continuously get the following invalid cast exception error.

我试过什么？使用 JavaScriptSerializer，使用http://jsontodatacontract.azurewebsites.net/抓取 stackoverflow 作为示例。太多的事情，在这一点上我心慌意乱。所以我不断收到以下无效转换异常错误。

 Conversion from type 'Dictionary(Of String,Object)' to type 'String' is not valid.

If anyone can help me out I would be very appreciative :)

如果有人可以帮助我，我将不胜感激:)

采纳答案by ??ssa P?ngj?rdenlarp

The JSON provided only has one element, so it will result in a collection (dictionary) of one. I added an "item" to be sure the code below worked and for illustration purposes. Proper indentation makes things easier to follow:

提供的 JSON 只有一个元素，所以它会产生一个集合（字典）。我添加了一个“项目”以确保下面的代码有效并用于说明目的。适当的缩进使事情更容易理解：

{
    "foo": {
        "HashTag": "12342345636",
        "companyname": "my test company",
        "LeadDetail": {
            "id": "1",
            "firstname": "ziggy",
            "lastname": "clark",
            "email": "[email protected]",
            "phone": "9874534444"
        }
    },
    "bar": {
        "HashTag": "02342345636",
        "companyname": "my test company2",
        "LeadDetail": {
            "id": "1",
            "firstname": "john",
            "lastname": "clark",
            "email": "[email protected]",
            "phone": "1874534444"
        }
    }
}

Starting with the most deeply indented, it is easy to see a LeadDetailclass with {ID, FirstName, etc). With more than one item (as in mine), this would repeat.

从缩进最深的开始，很容易看到LeadDetail带有 {ID、FirstName 等）的类。如果有多个项目（如我的），这会重复。

Then there are "foo" and "bar" objects with a little data and a LeadDetailobject. When you use any of the Robots, they will create a class for each. Mine would be named "foo" and "bar" but otherwise be identical. In the code below, I condensed this to one class named "Item". Then you can treat them (Foo and Bar) as a Dictionary(of String, Item)where their names are the keys.

然后是带有少量数据和LeadDetail对象的“foo”和“bar”对象。当您使用任何机器人时，它们都会为每个机器人创建一个类。我的将被命名为“foo”和“bar”，但在其他方面是相同的。在下面的代码中，我将其压缩为一个名为“Item”的类。然后您可以将它们（Foo 和 Bar）视为Dictionary(of String, Item)它们的名称是键的地方。

But there is one more, less obvious class/Type: The outer most {..}. The robot tools will create a class named "Example" or "RootObject". You dont need it or want it for a dictionary:

但是还有一个不那么明显的类/类型：最外面的{..}. 机器人工具将创建一个名为“Example”或“RootObject”的类。你不需要它或想要它作为字典：

' modified from VS's EDIT -> Paste Special -> JSON as Classes
Public Class Item           
    Public Property HashTag As String
    Public Property companyname As String
    Public Property LeadDetail As Leaddetail
End Class

Public Class Leaddetail
    Public Property id As String
    Public Property firstname As String
    Public Property lastname As String
    Public Property email As String
    Public Property phone As String
End Class

Then the code:

然后代码：

Dim jstr As String = ...
' use the Item/Value class not the container
Dim myJ = JsonConvert.DeserializeObject(Of Dictionary(Of String, Item))(jstr)

' print some of the data
For Each kvp As KeyValuePair(Of String, Item) In myJ
    Console.WriteLine("key {0}, CompName {1}, Contact: {2}", kvp.Key,
                      kvp.Value.companyname,
                      kvp.Value.LeadDetail.firstname)
Next

Output:

输出：

key: foo, CompName: my test company, Contact: ziggy
key: bar, CompName: my test company2, Contact: john

密钥：foo，CompName：我的测试公司，联系人：ziggy
密钥：bar，CompName：我的测试公司 2，联系人：john

If you run it on your original JSON, you get a dictionary of one.

如果在原始 JSON 上运行它，则会得到一个字典。

回答by Hans Olsson

Your classes don't seem to correspond properly to your Json.

您的课程似乎与您的 Json 不正确。

Using http://jsonutils.com/, it suggested that your classes should look like this:

使用http://jsonutils.com/，它建议您的类应如下所示：

Public Class LeadDetail
    Public Property id As String
    Public Property firstname As String
    Public Property lastname As String
    Public Property email As String
    Public Property phone As String
End Class

Public Class Value
    Public Property HashTag As String
    Public Property companyname As String
    Public Property LeadDetail As LeadDetail
End Class

Public Class LeadDetailCall
    Public Property value As Value
End Class